Imaging mode blooming suppression

ABSTRACT

A minimally invasive surgical system includes a scene anti-bloom process that allows switching between imaging modes on a stereoscopic display without causing a surgeon to look-away or being momentarily distracted by sudden changes in overall scene luminance. The process receives a switch from a first imaging mode to a second imaging mode. An overall scene luminance of a scene in the first imaging mode is less than an overall scene luminance of a scene in the second imaging mode. The process delays the switch to the second imaging mode until after an illumination output level of a visible illumination source has changed to a higher output level, and then switches to the second imaging mode.

RELATED APPLICATION

This application claims priority to and the benefit of:

-   -   U.S. Provisional Application No. 61/361,233 filed Jul. 2, 2010        entitled “IMAGING MODE BLOOMING SUPPRESSION,” naming as        inventors, Patrick O'Grady, Ian McDowall, and Brian D. Hoffman,        which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of Invention

Aspects of this invention are related to endoscopic imaging and are moreparticularly related to switching between imaging modes having differentoverall scene luminance.

2. Related Art

The da Vinci® Surgical System, commercialized by Intuitive Surgical,Inc., Sunnyvale, Calif., is a minimally invasive teleoperated surgicalsystem that offers patients many benefits, such as reduced trauma to thebody, faster recovery and shorter hospital stay. One key component ofthe da Vinci® Surgical System is a capability to provide two-channel(i.e., left and right) video capture and display of the captured visibleimages to provide stereoscopic viewing for the surgeon.

Such electronic stereoscopic imaging systems may output high definitionvideo images to the surgeon, and may allow features such as zoom toprovide a “magnified” view that allows the surgeon to identify specifictissue types and characteristics, as well as to work with increasedprecision. In a typical surgical field, however, certain tissue typesare difficult to identify, or tissue of interest may be at leastpartially obscured by other tissue. This complicates the surgicalprocedure.

SUMMARY

In one aspect, a minimally invasive surgical system includes a sceneanti-bloom process that allows switching between imaging modes on astereoscopic display without causing a surgeon either to look-away from,or be distracted by, sudden changes in overall scene luminance. In oneaspect, the process receives a command to switch from a first imagingmode to a second image mode of the display. An overall scene luminanceof a scene in the first imaging mode is less than an overall sceneluminance of a scene in the second imaging mode. The process delays theswitch to the second imaging mode until after an illumination outputlevel of a visible illumination source has changed to a higher outputlevel, and then switches to the second imaging mode.

In one aspect, the first and second imaging modes have a same normallevel of a display output gain of a display of the minimally invasivesurgical system. In this aspect, the delaying includes lowering thedisplay output gain of the display from the normal level. The delayingalso includes switching from a lower illumination output level of thevisible illumination source to a higher illumination output level of thevisible illumination source following lowering the display output gain.In another aspect, the switching the imaging mode includes restoring thedisplay output gain to the normal level.

A minimally invasive surgical system includes a display, an output gaincontrol unit coupled to the display, an imaging mode switch, and acontroller coupled to the output gain control unit and to the imagingmode switch. Following receipt of an imaging mode change command fromthe image mode switch, the controller configures the output gain controlunit to attenuate an output image by decreasing the brightness of theoutput image.

In one aspect, the system also includes an illuminator including a powerand level controller and a visible light source. The controllerconfigures the power and level controller to restore an output level ofthe visible light source from a reduced output level to a normalillumination output level. In another aspect, the reduced output levelcorresponds to the visible light source being powered off. In yetanother aspect, the reduced output level is less than one hundredpercent of the normal illumination output level. Following therestoration of the output level of the visible light source thecontroller configures the output gain control unit to display an imageon the display.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a high level diagrammatic view of a minimally invasiveteleoperated surgical system that includes an imaging mode controllerhaving a scene anti-bloom process.

FIG. 2 is a process flow diagram for one aspect of the scene anti-bloomprocess.

FIG. 3 is a more detailed process flow diagram for one aspect of thescene anti-bloom process.

FIG. 4 is a high level diagram of modules of the minimally invasivesurgical system.

In the drawings, the first digit of a reference number indicates thefigure in which the element with that reference number first appeared.

DETAILED DESCRIPTION

In one aspect, minimally invasive surgical system 100 (FIG. 1) includesa scene anti-bloom process 171 that facilitates switching betweenimaging modes on stereoscopic display 151 without causing a surgeon tolook away from or to be distracted by sudden changes in overall sceneluminance. In some conventional minimally invasive surgical systems,when the surgeon switches the imaging mode of stereoscopic display 151from a fluorescence imaging mode to a normal imaging mode, e.g.,switches from illuminating tissue 103 with illumination fromfluorescence illumination source 112 to illuminating tissue 103 with thenormal output illumination of white light illumination source 111, thedisplay of the scene that includes tissue 103 becomes extremely brightand washed out, i.e., the displayed scene blooms.

In these conventional minimally invasive surgical systems, the displayedscene is so bright that typically the surgeon may divert his or her eyesfrom display 151. As explained more completely below, aspects of thisinvention eliminate this blooming and so enhance the surgeon'sperformance, because the surgeon can continue viewing display 151 duringall imaging mode changes.

FIG. 1 is high level diagrammatic views of a minimally invasiveteleoperated surgical system 100, for example, the da Vinci® SurgicalSystem commercialized by Intuitive Surgical System, Inc. of SunnyvaleCalif. Surgical system 100 includes an imaging mode controller 170 withscene anti-bloom process 171. As explained more completely below, whenthe surgeon switches the imaging mode from scenes of tissue 103 with alow overall scene luminance (a first overall scene luminance) to sceneswith a high overall scene luminance (a second, higher overall sceneluminance), scene anti-bloom process 171 attenuates the brightness ofany scenes displayed on display 151 until after the illumination hasbeen changed and until after any causes of blooming associated with thechange in illumination have stabilized. Thus, scene anti-bloom process171 eliminates the very bright scenes that are encountered in theconventional minimally invasive surgical systems when the imaging modeis changed.

Prior to considering process 171 in further detail, it is informative tounderstand the operation of system 100 as illustrated in FIG. 1. Thereare other parts, cables etc. associated with the da Vinci® SurgicalSystem, but these are not illustrated in FIG. 1 to avoid detracting fromthe disclosure. Further information regarding minimally invasivesurgical systems may be found for example in U.S. patent applicationSer. No. 11/762,165 (filed Jun. 13, 2007; disclosing Minimally InvasiveSurgical System) and U.S. Pat. No. 6,331,181 (filed Dec. 18, 2001;disclosing Surgical Robotic Tools, Data Architecture, and Use), both ofwhich are incorporated herein by reference.

For example, while it is not shown in FIG. 1, system 100 includes a cartwith a plurality of servo controlled robotic manipulators. Eachmanipulator can be coupled to, and decoupled from master toolmanipulators on surgeon's console 150. A stereoscopic endoscope 101 ismounted on one of the manipulators. The interactions between the mastertool manipulators, the slave surgical devices, and stereoscopicendoscope 101 are the same as in a conventional system and so are knownto those knowledgeable in the field.

Also, as explained more completely below, acquired images of a surgicalsite are directed to stereoscopic display 151. However, each acquiredimage (left or right) can be directed to more places than just thisdisplay. For example, other monitors, video recorders, video codecs forremote display via the Internet can all be used with system 100. Thefollowing description is directed at eliminating blooming so that thesurgeon keeps his or her eyes on display 151. However, the processesdescribed herein are also applicable to any of the contexts of theseother devices. Therefore, eliminating blooming on display 151 isillustrative only and is not intended to be limiting.

Also, in the following example, a stereoscopic endoscope, left and rightacquisition and display paths are described. This also is illustrativeonly. The processes described more completely below also are applicableto monoscopic systems that switch between normal and fluorescenceimaging mode, as described herein.

As described more completely below, endoscope 101 provides left andright images of tissue 103 within a patient. The left and right imagesalso include images of any slave surgical devices in the field of viewof stereoscopic endoscope 101. The collection of images in a frameacquired from a channel of endoscope 101 is referred to herein as ascene. The acquired scene has an overall luminance. Overall luminance isused to distinguish the scene luminance from the luminance of individualimages in the acquired scene, i.e., the luminance is over all of theimages in the acquired scene.

In system 100, an illumination system, e.g., dual mode illuminator 110,is coupled to endoscope 101. Dual mode illuminator 110 includes a whitelight source 111 and a fluorescence excitation source 112. The on andoff state of each of sources 111 and 112 is independently controllableby power and level controller 115 in response to commands from imagingmode controller 170. In addition, at least the output level of whitelight source 111 is controlled by power and level controller 115 inresponse to commands from imaging mode controller 170.

Typically, three (or more) visible color components make up white light,i.e., white light includes a first visible color component, a secondvisible color component, and a third visible color component. Each ofthe three visible color components is a different visible colorcomponent, e.g., a red component, a green component, and a bluecomponent.

In one aspect, white light source 111 includes a source for each of thedifferent visible color illumination components. For a red-green-blueimplementation, in one example, the sources are lasers.

The use of lasers in white light source 111 is illustrative only and isnot intended to be limiting. White light source ill could also beimplemented with multiple laser diodes or light emitting diodes (LEDs)for example. Alternatively, white light source 111 could use a Xenonlamp with an elliptic back reflector and a long band pass coating tocreate broadband white illumination light for visible images. The use ofa Xenon lamp also is illustrative only and is not intended to belimiting. For example, a high pressure mercury arc lamp, other arclamps, or other broadband light sources may be used.

When the fluorescence excitation wavelength occurs outside the visiblespectrum (e.g., in the near infrared (NIR) spectrum), a laser module (orother energy source, such as a light-emitting diode or filtered whitelight) is used as fluorescence excitation source 112.

In one example, dual mode illuminator 110 has a normal imaging mode anda fluorescence imaging mode. In the normal imaging mode, white lightsource 111 provides illumination that illuminates tissue 103 in whitelight. The illumination output of white light source 111 in the normalimaging mode is referred to as the normal illumination output level ofwhite light source 111. Fluorescence excitation source 112 is not usedin the normal imaging mode.

In the fluorescence imaging mode, fluorescence excitation source 112 isturned on. Fluorescence excitation source 112 provides a fluorescenceexcitation illumination component that excites fluorescence from tissue.For example, narrow band light from fluorescence excitation source 112is used to excite tissue-specific fluorophores so that fluorescenceimages of specific tissue within the scene are acquired by cameras 120L,120R.

In the fluorescence imaging mode, white light source 111 provides, inone aspect, one or more visible color illumination components toilluminate tissue 103. If one or more visible color illuminationcomponents are used in the fluorescence imaging mode, the output levelof those visible color illumination components is reduced to one part inten relative to the normal illumination output level used in the normalimaging mode. In this aspect, both visible and fluorescence images areacquired. In another aspect, none of the visible color components ofwhite light are used when fluorescence excitation source 112 is on.

In any of the modes of operation of dual mode illuminator 110, the lightfrom the light source or light sources is directed into a fiber opticbundle 116. Fiber optic bundle 116 provides the light to an illuminationpath in stereoscopic endoscope 101 that in turn directs the light totissue 103.

Endoscope 101 also includes, in this aspect, two optical channels forpassing light emanating from tissue 103 and from any other objects inthe field of view of endoscope 101. Reflected white light or a reflectedvisible color component of white light forms a visible image or images.Fluorescence may be either visible light or non-visible light dependingon the fluorophore that is used. In the fluorescence imaging mode, anoverall scene luminance of an acquired frame is generally much less thanthe overall scene luminance of an acquired frame in the normal imagingmode.

The light from tissue 103 (FIG. 1) is passed by the stereoscopic opticalpath in endoscope 101 to cameras 120L, 120R. In the various modes ofoperation that correspond to the various imaging modes, left image CCD121L acquires a frame that includes a left image and right image CCD121R acquires a frame that includes a right image. Each of left imageCCD 121L and right image CCD 121R can be multiple CCDs that each capturea different visible color component; a single CCD with different regionsof the CCD that capture a particular visible color component, etc. Athree-chip CCD sensor is illustrative only. A single CMOS image sensorwith a color filter array or a three-CMOS color image sensor assemblymay also be used.

Camera 120L is coupled to a stereoscopic display 151 in surgeon'sconsole 150 by a left camera control unit 130L. Camera 120R is coupledto stereoscopic display 151 in surgeon's console 150 by a right cameracontrol unit 130R. Camera control units 130L, 130R receive signals froman imaging mode controller 170 and provide control signals to cameras120L, 120R. Each of camera control units 130L, 130R includes anautomatic gain controller (AGC) 131L, 131R.

In one aspect, each of camera control units 130L, 130R also includes anoutput gain control unit 132L, 132R that controls the display outputgain for display 151. The inclusion of output gain control units 132L,132R in camera control units 130L, 130R is illustrative only and is notintended to be limiting. In another aspect, output gain control units132L, 132R are units positioned between camera control units 130L, 130Rand display 151. In still another aspect, output gain control units132L, 132R are included in display 151.

Automatic gain controllers 131L, 131R automatically adjust the gain forthe acquired frames from cameras 120L and 120R. The output display gaincan be set by commands from imaging mode controller 170 to output gaincontrol units 132L, 132R.

When the illumination from dual mode illuminator 110 changes, theoverall scene luminance of the acquired frames change. In changing fromillumination in the fluorescence imaging mode to illumination in thenormal imaging mode, the automatic gain controllers 131L, 131R areconfigured for the relatively lower overall scene luminance of framesacquired in the fluorescence imaging mode. However, upon theillumination source switch, the acquired frames have the normal overallscene luminance, which is greater than the overall scene luminance forthe frames in the fluorescence imaging mode. Consequently, immediatelyfollowing the switch, the automatic gain controller is not configuredcorrectly, and in the conventional systems this contributed to the sceneblooming.

In one aspect, stereoscopic video output display 151, sometimes referredto as display 151, may be operated in various imaging modes. Forexample, in a normal imaging mode, only visible images are output todisplay 151. In fluorescence imaging mode, fluorescence images aresuperimposed on visible images to create augmented images, and theaugmented images are output to display 151. One technique forsuperimposing the images is described below.

The imaging mode of display 151, in one aspect, is toggled between thesetwo imaging modes by using imaging mode select switch 152, e.g., a footswitch, a double click of the master grips that control the surgicalinstruments, voice control, and other like switching methods. Inresponse to the user input, a MODE SWITCH check operation 252 (FIG. 2)in imaging mode select switch 152 sends a notification of the selectedimaging mode to an EVENT HANDLER 261 in a user interface 161. FIG. 2 isa process flow diagram of one aspect of a method to suppress blooming.

In response to the notification, EVENT HANDER 261 in user interface 161sends a mode switch command to system process 162. System process 162forwards the mode switch command to imaging mode controller 170 and alsoconfigures any other elements of system 100 needed to process theacquired images so that the surgeon is presented the requested imagingmode in display 151. System process 162 represents the variouscontrollers, etc. in system 100 that are not illustrated in FIG. 1.

MODE SWITCH check operation 271, in imaging mode controller 170,determines the direction of the change in overall scene luminance. Ifthe imaging mode is changed from the normal imaging mode to thefluorescence imaging mode, the direction of the change in overall sceneluminance is high to low. Conversely, if the imaging mode is changedfrom the fluorescence imaging mode to the normal imaging mode, thedirection of the change in overall scene luminance is low to high. Asexplained above, in the fluorescence imaging mode, the illuminationoutput from white light source 111 in illuminator 110 is less than theillumination output from white light source 111 from illuminator 110 inthe normal imaging mode.

When the imaging mode switch is low to high, MODE SWITCH check operation271 transfers to DELAY IMAGING MODE SWITCH process 272. In DELAY IMAGINGMODE SWITCH process 272, imaging mode controller 170 configures outputgain control units 132L, 132R to attenuate output images to display 151.Imaging mode controller 170 then sends a command to power and levelcontroller 115 to change the illumination source to white light source111 with the normal illumination output level. DELAY IMAGING MODE SWITCHprocess 272 transfers processing to SWITCH IMAGING MODE process 273.

In SWITCH IMAGING MODE process 273, imaging mode controller 170configures output gain control units 132L, 132R to allow display 151 todisplay images in the normal imaging mode. Since output images todisplay were greatly attenuated when the change in illumination wasmade, the prior art blooming is prevented. Thus, the surgeon sees asmooth transition from the fluorescence imaging mode to the normalimaging mode without any sudden bright distortion in the displayedscenes.

When the imaging mode switch command is from a high overall sceneluminance to a low overall scene luminance, MODE SWITCH check operation271 transfers to SWITCH ILLUMINATION process 274. In SWITCH ILLUMINATIONprocess 274, imaging mode controller 170 sends a command to power andlevel controller 115 to turn-on fluorescence excitation source 112 andto configure white light source 111 for the fluorescence imaging mode ofoperation. As explained above, in one aspect, white light source 111 isturned off.

In another aspect, in process 274, the output level of white lightsource 111 is reduced to one part in ten relative to the normalillumination output level of white light source 111 in the normalimaging mode. In yet another aspect, one or more visible color componentillumination sources are turned off and the output level of the visiblecolor component illumination sources that remain on is reduced to onepart in ten relative to the normal illumination output level of thosesources in the normal imaging mode. The output level reductions areillustrative only and are not intended to be limiting to the specificvalues described. In this direction of change in overall sceneluminance, it is unnecessary to block output to display 151 because theoverall scene luminance is being decreased and so blooming is not anissue.

FIG. 3 is a more detailed process flow diagram of one aspect of sceneanti-bloom process 171. Initially in process 171B when system 100 isinitialized, system process 162 calls INITIALIZE process 320. In thisaspect, INITIALIZE process 320 communicates with each of output gaincontrol units 132L, 132R, and instructs output gain control units 132L,132R to send processes 272A and 273A information necessary to change thedisplay output gains in output gain control units 132L, 132R. INITIALIZEprocess 320 also communicates with power and level controller 115 indual mode illuminator 110 to initialize power and level controller 115.Upon completion, INITIALIZE process 320 ends and returns.

Processes 271 and 274 were described above and so that description isincorporated herein by reference with respect to FIG. 3. When theimaging mode switch is low to high, processing transfers from MODESWITCH check operation 271 to DELAY IMAGING MODE SWITCH process 272A,which is an example of delay display switch process 272.

In process 272A, LOWER OUTPUT GAIN process 301 communicates with outputgain control units 132L, 132R and instructs output control gain units132L, 132R to lower the display output gain from the normal displayoutput gain used in the normal imaging mode. The display output gain islowered so that irrespective of the overall scene luminance of anacquired frame from cameras 120L, 120R, any images displayed onstereoscopic display 151 are greatly attenuated, i.e., display 151 goesdim.

In one aspect, as many as three different commands are issued to outputgain control units 132L, 132R over a 9600 Baud communication link.Hence, there is a delay associated with lowering the display outputgain. In this aspect, INITIALIZE TIMERS process 302 initializes a modeswitch timer that is used to provide configurable delays between variouscommands that are sent. If scene anti-bloom process 171B should failafter initiation of LOWER OUTPUT GAIN process 301 and before completionof RESTORE OUTPUT GAIN process 305, display 151 would be left in theblacked out state, which is unsafe. Thus, INITIALIZE TIMERS process 302also taps a system watchdog timer.

A system WATCHDOG TIMEOUT check operation 310 monitors the systemwatchdog timer. If the system watchdog timer times out, check operation310 transfers to a RESET process 311. In RESET process 311, cameracontrol units 130L, 130R are commanded to reload a defaultconfiguration, which is the normal imaging mode white light settings.RESET process 311 also commands power and level controller 115 to reloadthe default configuration, which turns off fluorescence excitationsource 112, if necessary; turns on white light source 111, if necessary;and sets white light source 111 at the normal illumination output level.This process restores acquisition of useful images by cameras 120L, 120Rthat are displayed on display 151.

Returning to INITIALIZE TIMERS process 302, after initializing the modeswitch timer, process 302 transfers to MODE SWITCH TIMEOUT checkoperation 303. When the mode switch timer times out, sufficient time haspassed that the necessary commands have been sent to output gain controlunits 132L, 132R during the time period, and the display output gains ofoutput gain control units 132L, 132R have been lowered. Thus, when themode switch timer times out, processing transfers to SWITCH ILLUMINATIONprocess 304.

In SWITCH ILLUMINATION process 304, a command is sent to power and levelcontroller 115 to turn-off fluorescence excitation source 112; toturn-on white light source 111, if necessary; and to restore white lightsource 111 to the normal illumination output level. In one aspect, twocommands are sent during process 304. This completes DELAY IMAGING MODEprocess 272A, and so SWITCH ILLUMINATION process 304 transfers to SWITCHIMAGING MODE process 273A, which is an example of SWITCH IMAGING MODEprocess 273.

RESTORE OUTPUT GAIN process 305, in SWITCH IMAGING MODE process 273A,communicates with output gain control units 132L, 132R and instructsoutput gain control units 132L, 132R to restore the display output gainto the normal display output gain of the normal imaging mode. When thedisplay output gain is restored to normal, any transients in automaticgain controllers 131L, 131R have died out. Thus, when the surgeonswitches the imaging mode from the fluorescence imaging mode to thenormal imaging mode there is no blooming. Anti-bloom process 171Btypically takes between 0.2 and 0.5 seconds to complete and so thedisplay goes momentarily dim and then switches to the normal imagingmode. Typically, however, the surgeon does not notice the display goingmomentarily dim and is not distracted by this momentary display change.

The particular time aspects in processes 171, 171A, 171B depend on thecamera control units used, the location of output gain control units132L, 132R, the speed of communication links, the processing power ofthe hardware processor etc. Thus, the timing of when the white lightsource is returned to the normal illumination output level may vary.However, in each instance, the white light source is returned to thenormal illumination output level after the display output gains havebeen lowered from the normal gain and before the display output gainsare returned to the normal gain. Also, if the communications with theoutput gain control units are more rapid, the time required for theautomatic gain controllers to settle out after the white light sourcehas been restored to the full output level may need to be explicitlyaccounted for with a timeout timer or some other means.

Thus, in one aspect, a plurality of programmable time delays are used inprocesses 171, 171A, 171B. For example, a first programmable time delay172 and a second programmable time delay 173 are used (FIG. 1). In oneaspect, first and second programmable time delays 172, 173 are storageregisters that are set to first and second values respectively duringinitialization of the process. The values are the delay time periods.

Storage registers are illustrative only and are not intended to belimiting. A storage register is an example of a storage element.

The delay time period of the delay in returning the white light sourceto the normal illumination output level is determined by firstprogrammable time delay 172. The delay time period of the delay inswitching the viewing mode after returning the white light source to thenormal illumination output level is determined by second programmabletime delay 173. The first and second programmable time delays 172, 173are chosen to provide the appropriate synchronization between left andright camera control units 130L, 130R and other equipment to eliminatethe blooming. Thus, either of first and second programmable time delays172, 173 can be set to zero if the delay is not needed.

In one aspect of the fluorescence imaging mode, as discussed above, thescene on display 151 includes a simultaneous display of a reflectedvisible light image of tissue referred to as a backlight image, and aseparately or simultaneously acquired enhanced image of tissue in thesame surgical site. The enhanced image of tissue may be captured withtechnologies such as, but not limited to, near-infrared (NIR)fluorescence, visible light fluorescence, multispectral imaging,fluorescence lifetime imaging, or a raster scan of non-visible lightcharacteristics that contains clinical information with spatialvariation. In addition, the enhanced image may be of an imageconstructed by overlaying point measurements of different types ofmeasurable tissue parameters such as tissue impedance, point detectionof cancer, or certain cell types on the clinical white light image.

Generally, in this mode of display the backlight image is desaturatedtoward a grayscale or a black/white image that is displayed to thesurgeon or clinician instead of a color reflected light image.Desaturation of any image pushes the red, green, and blue hues towardsgray thereby removing color from an image. Enhanced informationregarding the clinical image is captured using one or more enhancedimaging techniques and represented in the visible spectrum with one ormore colors in registration with the desaturated backlight image.

When the enhanced information, typically invisible to the unaided eye,is represented in the visible spectrum it is false colored. Examples offalse colors (also referred to as enhancement colors) to color theenhanced images are, but not limited to, green, blue, and purple thatmay be used to represent one or more types of signals in the non-visibleelectromagnetic spectrum detected by the enhanced imaging technology inthe enhanced images.

The color version of the enhanced image is registered to the desaturatedbacklight clinical image and blended with, superimposed on, or overlaidon top of (alternatively referred to as being combined with) thedesaturated clinical image. The combination of these two images in ablended image is displayed to the surgeon to increase the amount ofclinically relevant information, and to improve the detectability of lowsignal levels in the color enhanced images of the surgical site duringsurgery.

As the backlight clinical image is desaturated, the color information inthe image is removed but there is little loss in detail. The desaturatedclinical image is sufficient to identify anatomy, tissue landmarks, andsurgical instruments so that it allows safe manipulation thereof.Moreover with a desaturated clinical image, there is no loss in contrastof the enhanced image due to interference by a color representation of awhite light clinical image. The color enhanced image overlaid onto thedesaturated clinical image provides improved information contentregarding the surgical site to reduce the risk of injury to the patientand improve surgical efficiency. More detail about this mode of displayis presented in U.S. patent application Ser. No. 12/575,093 (filed Oct.7, 2009; disclosing Methods and Apparatus for Displaying EnhancedImaging Data on a Clinical Image), which is incorporated herein byreference in its entirety.

In the above methods, various modules and operations and/or processeswere described. Each of these operations or processes is part of amodule in central controller 190. While central controller 190 isillustrated as a single structure in FIG. 1, this is for ease ofillustration only. The elements of central controller 190 are typicallydistributed throughout system 100 at appropriate locations.

User interface module 461 (FIG. 4) is used to implement user interface161. Imaging mode controller module 470 is used to implement imagingmode controller 170. Similarly, scene anti-bloom module 471 is used toimplement scene anti-bloom process 171. The modules may be implementedin hardware, software that is executed on a processor, firmware or anycombination of hardware, software, or firmware. In one aspect, sceneanti-bloom module includes computer executable instructions stored inmemory 402. In this aspect, no hardware changes are required toimplement scene anti-bloom process 171.

When the modules include one or more instructions stored on anon-transitory storage medium, the described operations and/or processesare the result of retrieval and execution of the one or moreinstructions on at least one processor in processor module 401. Herein,a processor is a hardware element. The particular modules described areillustrative only and are not intended to be limiting. In view of thedisclosure, one knowledgeable in the field can combine modules togetheror separate a module into one or more additional modules.

The above description and the accompanying drawings that illustrateaspects and embodiments of the present inventions should not be taken aslimiting—the claims define the protected inventions. Various mechanical,compositional, structural, electrical, and operational changes may bemade without departing from the spirit and scope of this description andthe claims. In some instances, well-known circuits, structures, andtechniques have not been shown or described in detail to avoid obscuringthe invention.

Further, this description's terminology is not intended to limit theinvention. For example, spatially relative terms—such as “beneath”,“below”, “lower”, “above”, “upper”, “proximal”, “distal”, and thelike—may be used to describe one element's or feature's relationship toanother element or feature as illustrated in the figures. Thesespatially relative terms are intended to encompass different positions(i.e., locations) and orientations (i.e., rotational placements) of thedevice in use or operation in addition to the position and orientationshown in the figures. For example, if the device in the figures isturned over, elements described as “below” or “beneath” other elementsor features would then be “above” or “over” the other elements orfeatures. Thus, the exemplary term “below” can encompass both positionsand orientations of above and below. The device may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly. Likewise,descriptions of movement along and around various axes include variousspecial device positions and orientations.

The singular forms “a”, “an”, and “the” are intended to include theplural forms as well, unless the context indicates otherwise. The terms“comprises”, “comprising”, “includes”, and the like specify the presenceof stated features, steps, operations, elements, and/or components butdo not preclude the presence or addition of one or more other features,steps, operations, elements, components, and/or groups. Componentsdescribed as coupled may be electrically or mechanically directlycoupled, or they may be indirectly coupled via one or more intermediatecomponents.

Memory refers to a volatile memory, a non-volatile memory, or anycombination of the two. A processor is coupled to a memory containinginstructions executed by the processor. This could be accomplishedwithin a computer system, or alternatively via a connection to anothercomputer via modems and analog lines, or digital interfaces and adigital carrier line.

Herein, a computer program product includes a non-transitory mediumconfigured to store computer readable code needed for any one or anycombination of the operations described with respect to processes 171,171A or 171B in which computer readable code for any one or anycombination of operations described with respect to processes 171, 171Aor 171B is stored. Some examples of computer program products are CD-ROMdiscs, DVD discs, flash memory, ROM cards, floppy discs, magnetic tapes,computer hard drives, servers on a network and signals transmitted overa network representing computer readable program code. A tangiblenon-transitory computer program product includes a tangiblenon-transitory medium configured to store computer readable instructionsfor any one of, or any combination of operations described with respectto processes 171, 171A or 171B or in which computer readableinstructions for any one of, or any combination of operations describedwith respect to the scene anti-bloom process 171, 171A or 171B arestored. Tangible non-transitory computer program products include CD-ROMdiscs, DVD discs, flash memory, ROM cards, floppy discs, magnetic tapes,computer hard drives and other physical non-transitory storage mediums.

In view of this disclosure, instructions used in any one of, or anycombination of operations described with respect to the processes 171,171A or 171B can be implemented in a wide variety of computer systemconfigurations using an operating system and computer programminglanguage of interest to the user.

All examples and illustrative references are non-limiting and should notbe used to limit the claims to specific implementations and embodimentsdescribed herein and their equivalents. The headings are solely forformatting and should not be used to limit the subject matter in anyway, because text under one heading may cross reference or apply to textunder one or more headings. Finally, in view of this disclosure,particular features described in relation to one aspect or embodimentmay be applied to other disclosed aspects or embodiments of theinvention, even though not specifically shown in the drawings ordescribed in the text.

We claim:
 1. A method comprising: receiving, by a controller in asurgical system, a command to switch from a first imaging mode during asurgical procedure to a second imaging mode during the surgicalprocedure, wherein the first and second imaging modes have differentnon-zero illumination levels, wherein the first imaging mode has areduced visible illumination output level of a visible illuminationsource relative to a normal visible illumination output level of thevisible illumination source in the second imaging mode, wherein in thefirst and second imaging modes, scenes are acquired for display, whereinthe first and second imaging modes each have a normal level of a displayoutput gain of a display of the surgical system, and wherein an overallscene luminance of an acquired scene in the first imaging mode is lessthan an overall scene luminance of an acquired scene in the secondimaging mode; delaying, by the controller, the switch to the secondimaging mode until after a visible illumination output level of thevisible illumination source has changed from a lower visibleillumination output level to a higher visible illumination output level,wherein the delaying further comprises lowering the display output gainof an output gain control unit from the normal level of the firstimaging mode, wherein the output gain control unit is coupled between anautomatic gain controller and the display; and switching, by thecontroller, to the second imaging mode after the output level of thevisible illumination source has changed from the lower visibleillumination output level to the higher visible illumination outputlevel.
 2. The method of claim 1, wherein the delaying further comprises:switching from the lower visible illumination output level of thevisible illumination source to the higher visible illumination outputlevel of the visible illumination source following the lowering thedisplay output gain.
 3. The method of claim 1, wherein the switching tothe second imaging mode comprises: restoring the display output gain tothe normal level of the second imaging mode.
 4. The method of claim 1,wherein the first imaging mode includes displaying a fluorescence imageon the display, and wherein the second imaging mode includes displayinga reflected visible light image on the display.
 5. The method of claim1, wherein the delaying further comprises delaying for a programmabledelay time period.
 6. The method of claim 1, wherein said switchingfurther comprises: delaying the switching for a delay time period afterthe visible illumination output level of the visible illumination sourcehas changed and then performing the switching.
 7. The method of claim 6,wherein the delaying the switching comprises delaying the switching fora programmable delay time period.
 8. A surgical system comprising: adisplay; a camera control unit including an automatic gain controller;an output gain control unit coupled between the automatic gaincontroller and the display; an imaging mode switch, the imaging modeswitch being configured to select one of a plurality of imaging modes,the plurality of imaging modes including a first imaging mode during asurgical procedure and a second imaging mode during the surgicalprocedure, wherein in the first and second imaging modes, scenes areacquired for display, and wherein an overall scene luminance of anacquired scene in the first imaging mode is less than an overall sceneluminance of an acquired scene in the second imaging mode; anilluminator comprising a power and level controller and a visible lightillumination source, the visible light illumination source being coupledto the power and level controller; and a controller coupled to theoutput gain control unit, to the power and level controller, and to theimaging mode switch, following receipt of an imaging mode change commandfrom the imaging mode switch, the imaging mode change command being acommand to change from the first imaging mode during the surgicalprocedure to the second imaging mode during the surgical procedure, thefirst and second imaging modes having different non-zero illuminationlevels, the first imaging mode having a reduced visible illuminationoutput level relative to a normal visible illumination output level ofthe second imaging mode, the controller being configured to delay theimage mode change until after an illumination output level change of thevisible light illumination source from the reduced visible illuminationoutput level to the normal visible illumination output level, thecontroller being configured to configure the output gain control unit toattenuate any image output to the display during the delay, thecontroller being configured to configure the power and level controllerto restore an illumination output level of the visible lightillumination source from the reduced visible illumination output levelto the normal visible illumination output level during the delay, andthe controller being configured to switch to the second imaging modeafter the normal visible illumination output level of the visible lightillumination source has been restored.
 9. The system of claim 8, whereinthe reduced visible illumination output level corresponds to the visiblelight illumination source being powered off.
 10. The system of claim 8,wherein the reduced visible illumination output level is less than onehundred percent of the normal visible illumination output level.
 11. Thesystem of claim 8, further comprising: a programmable time delay storageelement comprising a delay time period before the controller configuresthe power and level controller to restore the normal visibleillumination output level.
 12. The system of claim 8, wherein followingthe restoration of the normal visible illumination output level of thevisible light illumination source, the controller configures the cameracontrol unit to display an image on the display.
 13. The system of claim12, further comprising: a programmable time delay storage elementcomprising a delay time period after the restoration of the normalvisible illumination output level of the visible light illuminationsource by the controller and before the controller configures the cameracontrol unit to display an image on the display.
 14. The system of claim8, wherein the output gain control unit is included in the cameracontrol unit.
 15. A method comprising: lowering an output gain of adisplay from the normal level of a first imaging mode following receiptof an imaging mode switch command by a controller in a surgical system,the lowering being by the controller, the imaging mode switch commandbeing a command to switch from the first imaging mode to a secondimaging mode, wherein the first and second imaging modes have differentnon-zero illumination levels, wherein the first imaging mode has areduced visible illumination output level of an illumination unitrelative to a normal visible illumination output level of theillumination unit in the second imaging mode, wherein in the first andsecond imaging modes, scenes are acquired for display, and wherein anoverall scene luminance of an acquired scene in the first imaging modeis less than an overall scene luminance of an acquired scene in thesecond imaging mode; commanding the illumination unit to switch from afirst visible illumination level to a second visible illumination levelfollowing a first predetermined time period after the lowering, thecommanding being by the controller, wherein the second visibleillumination level is larger than the first visible illumination level;and restoring the output gain of the display, the restoring being by thecontroller, wherein the output gain of the display is different from anautomatic gain controlled by an automatic gain controller.
 16. Themethod of claim 15, further comprising delaying the restoring a secondpredetermined time period following the illumination unit switching tothe second visible illumination level.